The present invention relates to a post-processing apparatus for trimming the edge of the center-folded and saddle-stitched sheets on which images outputted from an image-forming apparatus have been recorded, and also relates to an image-forming system comprising the aforementioned post-processing apparatus.
Conventionally, the printing industry has achieved the practical use of a post-processing apparatus comprising a trimming apparatus for trimming the edge of a booklet which has been saddle-stitched and center-folded.
Also recently, there has been presented a post-processing apparatus, incorporating a trimming apparatus, which saddle-stitches and center-folds the sheets having images created by an image-forming apparatus, such as a copier, printer, etc., in order to bind them as a booklet like a weekly magazine, and then trims the edge of the booklet by means of the built-in trimming apparatus to neatly align the edge.
A trimming apparatus disclosed in patent document 1 comprises a lower transporting belt for transporting a saddle-stitched and center-folded booklet, a contact-pressing means for contact-pressing the upper surface of the booklet loaded on the lower transporting belt, a lifting means for lifting the contact-pressing means, and a drive means for driving the lifting means, wherein the lifting means and the drive means are located below the lower transporting belt.
A trimming apparatus disclosed in patent document 2 has a booklet storing means which stores a plurality of booklets that have been trimmed, wherein the booklets are held with the folds face up and their sheets pressed against one another.
[Patent Document 1] Official Gazette of Japanese Patent Tokkai 2001-240296
[Patent Document 2] Official Gazette of Japanese Patent Tokkai 2001-240288
As shown in patent documents 1 and 2, in the conventional trimming apparatus, a saddle-stitched and center-folded booklet is transported by a rotating transporting belt, inserted into a trimmer portion of the trimming means with the booklet's fold leading, stops at a prescribed location when the leading edge of the booklet abuts against a stopper protruding into a booklet transporting passage, and then the booklet's trailing edge in the transporting direction is trimmed by a trimming means while the booklet is contact-pressed by a contact-pressing means that can be lifted.
In any of these conventional post-processing apparatus and trimming apparatus, a transporting path to transport the sheets is fixedly arranged with respect to the apparatus. Therefore, there is only a small degree of freedom for an arrangement of each processing unit, and this results in large size of the apparatus.
The present invention provides a post-processing apparatus having a large degree of freedom for arranging each processing unit in the apparatus.